Center and surface testing indicator



D. McDUFF. CENTER AND SURFACE TESTING INDICATOR.

APPLICATION FILED OCT. 21, I920.

Patented Aug- ];5, 1922.

- ter and Surface TestingTndicatorsiand I DANIEL MGDUFF, r DORCHEST'EB; MASSACHUSETTS.

CENTER AND sunr ses rnsr nve r rnrcaroa.

T all-I 112 mm, it may concern i Be it KIIOWII that T, .DANIEL MoD Fr,

a citizen of the United States, residing at Dorchester, in the county of. Suffolk and State of Massachusetts, have invented cer tain new and useful Improvements in Cendo hereby declare the following to be a full,

clear, and exact description of the invention,

such as will enable others skilled in the'art to which it appertains to make and use the same.

-This invention relates to u an indicator adapted to be used as a center or surface tester. The object of the invention is to improve the construction of such indicators to provide'a more durable, simple and effif.

cient construction. 1

To these ends one feature of the invention contemplates a construction of 1nd1cator comprising a supporting member, a flexible feeler mounted upon the supporting memher, and an indicating member arranged to feeler.

be 'moved by movements of the flexible side in the'improved construction of indicator by which allof the parts of the ind cator are assembled with rigid connections,

will be pointed thus producing a durable instrument and one in whiclrthe usual lost motion between the feeler and its support is eliminated;

These and other features of the invention out in the specification and claims. i

In the drawing illustrating the preferred embodiment of the invention, Fig 1 illus-.

porting member, preferably by a spring rigidly secured to the supporting member. An indicating member is operatively connected with the feeler to be moved by flexural' movements of the feeler. The feeler is adapted to be fiexurally moved by move inents of the center of the work (if the instrument is used as'a center tester) and also by variations in the surface of the work (when the instrument is used as a surface tester). i The preferred embodiment of the inven- "Specification of LettersP-atent. Pgginted Other features ofthe invention retion or-supporting meniber1'0 is provided with a-stud 12 secured therein adapted to pass t'hrough a hole ina bar-'l3 or other instrument secured in thetoolpost" of'a lathe" or similar 'machine tool. A nut 14 is and operates-to secure the bo'dy 'por'tion in fixed relation on thebar l3and thereby to the tool post of thelathe. A feeler-"16 comprising a wire 20, the end of which is pointed to form a centeringpin 17, is driven into asocket2& at the end of the body por 13101110 so as to berigidly mounted'thereim Between the body portion 10 andthe feeler tenedsurfaces 25, 26. The surfacef' ex tends horizontally and the" surface 26- extends vertically thus forming a spring ca p'ableof flexureinftwo directions between the feeler" and the body. portion10,-

Aug.15*,1 922. Application fi1ed.0ctoher{21,'1920. Seria1'Noj418,354.

tion is described as follows'i- Thebodypori:

screwed on the threaded endof the *stud 12 16, thewire 20 is provided with two fla- The feeler 16 further comprises a' spheri cal head '30 'screwed'uponfthe end, of the wire 20,.as shown-inFig'.1, and whichis,

adapted to be'fiexurally movedjtherewith.

The spherical head 30 is'pro vide d 'withh 'proj ecting 'sleeve32 embracing the wire'20", v and theien'd' of *which. is received within an enlarged socket 34: in the end'of'the body portion 10. In the normal use of the instrument, as the feeler 16 is moved back and forththe sleeve 32 engages the inside' surface of the" socket 34, and in this manner prevents undue movements of thefeeler, so: that excesslvestrain is eliminated from the double leaf spring; A thin flat pointer 33 'is soldered or otherwise secured to the spherical head'30 andthe freev end 38 ofthe pointer is arranged'to traverse a graduated scale 40 upon the upper surface of the body portion 10. -Arestraining wire l4 secured to the body portion is extended across the graduated scale 4:0 and serves to limitthe upward movement of the'end of the pointer. Z vIn using the indicator as a centertester, the'body portion 10 is"s'ecured' to the tool 1 postf ofthelathe or other machine tool in i I 10 5 A cator is then run forwardly until the center ingpin 17 of fth'e feeler lGiengages a p rethe mannerindicated in Fig. 1. The indiformed hole in the center of the work and whose position with .relationto the center of the chuck itis desired to'test. If the its positionof the preformed hole in the work lies without thetrue centerlthen as the work is oscillated the centering pin 17 being held in engagement with the "preformed hole, is t preformed hole from the true center.

caused to oscillate in a circle about the true center. The movements of the centering pin 17 are transmitted through the spherical head 30 to the end of the elongated pointer and operate to causethe latter to oscillate back and forth across the, graduated scale. The extent to which the end of the pointer moves upon each side of the central line or zero position of the pointer quantitatively indicates the radial distance 01": the The position Ofitllt) work in the chuck may then be adjusted and the position of the pre formed hole again tested until it is made .to coincide with the true center.

it, will be observed that the elongated pointer is of such construction that it may be readily flexed vertically bv .movement of the teeler in a vertical direction. It will therefore be apparent thatduring the use of the instrument as the feeler is oscillated in a circle, the vertical movements of the teeler are taken up by the tiexure of the .thin fiat pointer, with the result that the end 38 of the pointer is only moved to a smallest-eat .in a verticaldirection, and that the oscillations of the teeler in a horizontal direction. are quantitatively. transmitted to the end oi the pointer so as to cause it to swing in direct accordance with the .entent of the oscillations. I

in ,using. the instrument "for testing inside suriacesv the spherical. head 30 is giitiliized' as aiioeler .and the variations in tllel;patl1.0fi rotation oi the inside surface Itroma true circle indicate by means of the pointer, the extentthat the work varies from a true central position.

7 When the instrument is usedin connection with a surface gage the stud 12 is provided with washers 50, 52 having cooperating recessed portions 53 within which the spindle 45 of the surface gage .is clamped by the knurled nut 14: in the manner illustrated in 3. The spherical head 30 is used as a. eler when the instrument is used for surface testing. I

' From the description thus far it will be observed that the improved indicator is simple in construction, andthat the double leatspring connecting the teeler with the body portion enables a. very sensitive .teelting act-lento be secured, so that. small varia- 1 ,eaasev on and inovably supported thereby, and an indicating member arranged. to be moved bynios 'ements oi the teeter upon fiexure or surface tester comprising a supporting member, a feeler, spring connecting the ifeeler and supporting.member comprising the sole support for the 'i'eeler, and an inclicating member arange" to be moved by movements of the feeler.

3. nn indicator adapted for use-as a center or surface tester comprising a supporting member, a teeler, a spring capable of tlexure in two directions connectin the teeler and supporting mcmber and which the teeler is flexibly connected to the supporting memher, and an indicating member arranged to be moved by movements of the teeler.-

t. fin indicator adapted for use as a center or surface tester comprising a supporting member, a i rible member secured to the 16111 061; teeler mounted therely supported thereby, and an on ad mov indicating member arranged to be moved by movements of the teeler upon tienure of the .tiexible member, said teeler beingfprovided with aqcentering pin and spherical head.

[in indicator adapted for use as a center or suriace tester comprising a supporting memben a te'eler havinga centering pin and a spherical head, spring rigidly secured to. the supporting member and by which the fecleris supported, and a pointer carriedbyi the recicr arranged to move therewith.

6. l or surlace tester comprising a supporting member, a wire rigidly secured thereto, the outer end of which is pointed to form a centering pin, a spherical head screwed unon indicator adapted for use as a center the outer end of said 'wirm and a pointer secured to and carried by said spherical head and arranged to bemoved by tiexurc of said wire. I

7. An indicator adapted tor use as a center or surface tester comprising a supporting member, flexible member secured to the supporting member, a teeler mounted thereonand mo -vably supported thereby. an indicating member arranged to be moved by movements of thej-teeler upon 'tlexure ot the flexible member, and means for limitingthe extent ofmovements of the :eeler.

8. Anindicator adapted for useas a center or surface tester comprising a supporting member, a ieeler flexibly mounted thereon and having a sphericalheadand centering pin, a pointer carried by the spherical head arranged to be moved therewith, and a sleeve secured to said spherical head arranged to cooperate with limit the extent of movements of the feelers 'DANEL McDUFF.

the supporting member to i 

